Wondering what would be the best for forensics research SSD or windows?. In terms of effectiveness. I see many researches on SSD since 2013. But windows forensics not that much especially the latest version.

I want my topic not be repetitive as well as helpful in my career. Therefore, I need your opinion which is better SSD forensics or windows forensics .

Wondering what would be the best for forensics research SSD or windows?.

'Best' is not easy to evaluate. Anything that provides new and generally useful information is good. Anything that provides corrected and generally useful information is good. Repeating research that already has been done can be good (if it confirms a doubtful result) or useless (it doesn't add anything new).

It's like map making: adding (correct) information to a map is good, correcting information is also good. But just repainting countries in new colours is not clearly useful.

In terms of effectiveness. I see many researches on SSD since 2013. But windows forensics not that much especially the latest version.

Not sure I follow you: but don't confuse quantity with quality. Does any of these stuff youre referring to fill in new areas, confirm previously done research or do anything else that is useful?

Windows seems a more wide and open area for research.

I want my topic not be repetitive as well as helpful in my career.

And what is that career? Where is your goal?

And where are you in your career? Are you preparing for a Ph.D.? Or postgraduate research? Or ... are you only learning to research? If you're a student, talk to your tutor or equivalent: it becomes a 'how do I learn to research' question. Or is your career none of these, but something else entirely?

Find a question that you have some interest in that's either unresearched or needs complementary research due to later developments, and work that. If effectiveness or how much it furthers your career is more important ... I'm not likely to be able to help in any way.